The land that is now Canada has been inhabited for millennia by various Aboriginal peoples. Beginning in the late 15th century, British and French colonial expeditions explored, and later settled, the region's Atlantic coast. France ceded nearly all of its colonies in North America to Britain in 1763 after the Seven Years War.. In 1867, with the union of three British North American colonies through Confederation, Canada was formed as a federal dominion of four provinces. This began an accretion of provinces and territories and a process of increasing autonomy, culminating in the Canada Act 1982.